The present invention relates to a jack for a plug-jack combination. More particularly, the invention relates to such a jack having a spark protection sleeve and a jack contact. Such a plug-jack combination is known, for example, from German Patent DE-C 197 22 543 (which corresponds to U.S. Pat. No. 6,068,498 to Strack). There, a jack is illustrated in which a spark protection sleeve is pushed onto a jack contact. The spark protection sleeve is plastically deformed in order to implement a form-fitting seat on the jack. In addition, the contact lamellae forming the contact part of the jack contact are bent inward in order to produce a certain pretensioning of the jack.
The large forces which must be applied to deform the spark protection sleeve and to deform the contact lamellae are burdensome and disadvantageous in the production process. Specifically, the jack, in its final fabricated state, can easily suffer from alignment errors of the actual insertion opening, or the contact opening, on the contact part of the jack contact in relation to the introduction opening on the spark protection sleeve.
With respect, in particular, to the form fit that connects the spark protection sleeve and the jack contact, produced by deforming the spark protection sleeve, this means that typically the spark protection sleeve is pressed in, flattened and/or mortised at four diametrically opposing points, in order, thereby, to clinch a part of the spark protection sleeve with the jack contact. A ring groove may be provided in the jack contact for this purpose, into which the deformed regions of the spark protection sleeve then engage like barbs. This deformation of the spark protection sleeve, and the large forces associated with this deformation, can, however, give rise to alignment errors between the spark protection sleeve and the jack contact.
Further, with respect to the contact lamellae, in the extreme case, this conventional approach can lead to a situation where one contact lamella is not deformed or flattened at all while the other contact lamellae are so greatly deformed that they project into the insertion opening of the spark protection sleeve. Specifically, they are bent into the insertion opening to such an extreme that a plug pin runs into the front edges of the inwardly projecting contact lamellae as the plug pin is inserted into the opening of the spark protection sleeve, and thereby destroys the lamellae and/or pushes the jack contact out of the housing of the jack.
Finally, GDR Patent 67 484 discloses a contact sleeve having a laminar spring, in which the laminar spring is fixed flush in a sleeve using two ribs. This arrangement is disadvantageous, however, due to the high dimensional precision required in the region of the planar surfaces that are formed by the ribs and the adjoining regions of the sleeve.